"""
Storage paths and layout for /data/users/<username>/notebooks/...
All paths are derived from username and notebook_id; no global mutable state.
"""
from pathlib import Path
from typing import Optional

from backend.config import CHROMA_COLLECTION_NAME
from backend.utils import ensure_dir, user_data_dir


def user_root(username: str) -> Path:
    return user_data_dir(username)


def notebooks_index_path(username: str) -> Path:
    return user_root(username) / "notebooks" / "index.json"


def notebook_dir(username: str, notebook_id: str) -> Path:
    return user_root(username) / "notebooks" / notebook_id


def files_raw_dir(username: str, notebook_id: str) -> Path:
    return ensure_dir(notebook_dir(username, notebook_id) / "files_raw")


def files_extracted_dir(username: str, notebook_id: str) -> Path:
    return ensure_dir(notebook_dir(username, notebook_id) / "files_extracted")


def sources_json_path(username: str, notebook_id: str) -> Path:
    return notebook_dir(username, notebook_id) / "sources.json"


def chroma_persist_dir(username: str, notebook_id: str) -> Path:
    return ensure_dir(notebook_dir(username, notebook_id) / "chroma")


def chat_messages_path(username: str, notebook_id: str) -> Path:
    return ensure_dir(notebook_dir(username, notebook_id) / "chat") / "messages.jsonl"


def artifacts_root(username: str, notebook_id: str) -> Path:
    return ensure_dir(notebook_dir(username, notebook_id) / "artifacts")


def artifacts_index_path(username: str, notebook_id: str) -> Path:
    return artifacts_root(username, notebook_id) / "index.json"


def reports_dir(username: str, notebook_id: str) -> Path:
    return ensure_dir(artifacts_root(username, notebook_id) / "reports")


def quizzes_dir(username: str, notebook_id: str) -> Path:
    return ensure_dir(artifacts_root(username, notebook_id) / "quizzes")


def podcasts_dir(username: str, notebook_id: str) -> Path:
    return ensure_dir(artifacts_root(username, notebook_id) / "podcasts")


def get_chroma_collection_name() -> str:
    return CHROMA_COLLECTION_NAME